The invention relates to an active differential for the controlled distribution of a drive torque generated by a drive motor to two output shafts, including a planetary gear train for coupling the output shafts to a drive shaft of the drive motor and a distributor shaft to a distributor motor, wherein the distribution of drive torque to the output shafts depends on a torque exerted by the distributor motor.
Active differentials are used to distribute drive torques to a plurality of, in particular two, drive shafts. The differential thus allows the two output shafts to have different rotational speeds. When the differential is operated without an additional distributor motor or a complete or partial locking of the differential, the same torques are transmitted to both output shafts. Active intervention in a differential which changes the torque distribution to the output shafts depending on a further introduced torque allows a flexible distribution of torques.
Active differentials are used in particular in motor vehicles for the distribution of the drive torque from a drive motor to the driven wheels of the motor vehicle. In the automotive segment, the use of such an active differential is often referred to as “torque vectoring” or “active yaw”. The use of an active differential in the motor vehicle allows in particular an active influencing of the yaw angle of the motor vehicle, since the torques to the individual wheels and thus the forces being transmitted to the respective wheel on the roadway can be separately controlled or adjusted by the active differential.
In particular, when using an active differential in a motor vehicle, it is possible that high loads occur in the differential. Such high loads may occur especially when the rotational speeds of the output shafts are greatly different, or highly different torques work via the output shafts on the differential. It is also possible that, as a result of different response times of different vehicle systems, a large torque is transmitted from a drive motor to the wheels while these wheels are braked. The active differential is also heavily loaded in this case. In view of these high loads, both the service lives of the mechanical elements of the differential and the service times of power electronic components in the active differential can be reduced.